Clicking into custom time Field corrupts data
I have a custom time field with Minutes:Seconds:Milliseconds
Whenever I click into this field to make changes a date and time pops up because the date format for the field gets changed to Automatic and my custom format - "Multiple". There is no way I can see to edit the original data, it's replaced by a date.
https://dl.dropboxusercontent.com/s/uklpx6ujmw7bats/Numbers%20Date.mov?dl=0
iMac, macOS High Sierra (10.13.2)